Photovoltaic solar panels are finding expanded use both by industry and in the home environment not only as an alternate energy source to supplement conventional utility power, but for many "stand alone" applications in isolated regions. For the most part, the solar panel installations are structured to perform in conjunction with rechargeable batteries, direct application of the panel outputs to other types of loads being somewhat limited by their performance characteristics. In the latter regard, a typical solar activated photovoltaic panel will exhibit a peak power characteristic having an output voltage for example at 16 volts which diminishes in the presence of loading and further will exhibit a substantially constant current, i.e. 1 amp which remains constant notwithstanding the noted voltage alterations. As a consequence of this characteristic, the panels usually are not operated at their optimum power capacities. Typically, manufacturers of the panels produce them in panel units exhibiting nominal 16 volt level peak power characteristics with a constant 1 amp current output. Thus, for an installation, for example, where a solar panel is employed in a charging relationship with a 12 volt battery, a 16 volt or 32 volt panel combination may be selected. Similarly, where a 24 volt battery installation is to be charged, the noted panel combination exhibiting 32 volts at peak power characteristic may be employed. Because the panel output voltage will be drawn down to the battery voltage in a recharging relationship, even though the current values remain stable, a resultant drop in available wattage for this recharging function becomes significant. As a consequence, the extent of solar panel usage must be enhanced to accommodate for this performance below the peak power capabilities of the panels.
Where photovoltaic solar panels are employed to power other forms of loads such as refrigeration compressor motors or the like, a similar enlargement of the panel array must be provided to accommodate for the temporarily encountered heavier start-up power demands. For example, a refrigeration motor may require 60 watts in continuous normal operation but an 80 watt start-up demand. Thus, this form of transient load will draw down peak voltage of the panels, however, the corresponding current levels will not be increased to maintain power. As a consequence, the powering of such loads from a photovoltaic panel array requires a significant expansion in expensive panel capacity to meet a temporary load demand.
From the foregoing it may be observed that significant improvements in the efficiencies of the photovoltaic solar panel powering systems can be realized if they can be operated such that their peak power voltage levels are maintained. Such performance would permit panel assemblages of lesser extent and important reductions in the cost of a given installation. Further, a much broadened range of applications of these power sources would become available.